Multiplier works fine. What you see might not reflect the actual damage, but actually the enemy get damaged as what you set. eg. x100 and you did 1000 on screen, so the actual damage done in the background is 100,000 and thats what the game registers. The trick is though, you gotta tick✅ BOTH Atk AND Def to make it activated. The DEF works as long as your total HP is higher than dmg done by enemy. You’ll see your hp go down then heal back up to full again. If they outdmg you, you’d still die.
The only place it doesnt work is in Raid (Calamity). You better set Atk at 1x and Def at 100x, coz in the end the game will register only the non-modded damage.
One more thing, if you die (get 1shotted) when “Always your turn” is on, game will freeze and for Obelisk/Coliseum/Raid, it will still use up your respective energies used. For Story/Primehall, if it freeze and you restart game it wouldn’t use up the energy.
Hope that helps everyone